1. Field of the Invention
This invention relates to method and apparatus for manufacture of panels, particularly for assembly and fastening
2. The Prior Art
Assembling and fastening together elements of reinforced panels is a multi-step process. For example, elements of an aircraft panel, such as a wing panel, include, e.g. an aluminum web or sheet, a plurality of reinforcing members or stringers and fastening means therefor. Once these elements are located, a problem lies in the high man-hour requirements needed to prepare and position them for assembly in an automatic fastening operation such as found in modern aircraft assembly plants. Such preparation process would normally require the manual drilling and installation of many, (e.g. 500) temporary fasteners (tacking) to hold the reinforced panel members together, as guided by a jig for that purpose.
However the drilling of the panel and stringers even for temporary fasteners, results in fragments or burrs being generated at the drilling points, including at the contact faces of the stringers and panel. Accordingly, after panel assembly and such drilling and tacking, the tacks must be removed, the elements disassembled and the fastening apertures deburred, after which the elements are reassembled and the tacks are reinserted in the drilled apertures to refasten panel and stringers together.
After such (doubly) laborious tacking and retacking process, the wing reassembly is then removed from the assembly jig and transferred to a fastening stage to be fastened, e.g. by rivets.
In the prior art, several patents relate to aircraft structures and methods of assembly U.S. Pat. No. 3,827,661 to Ryan et al. (1974), U.S. Pat. No. 3,643,900 to Maloney (1972), U.S. Pat. No. 2,567,124 to Roberts (1951), U.S. Pat. No. 2,430,438, to Watter et al. (1943) and U.S. Pat. No. 2,451,454 to Watter (1948). Although these patents relate to the assembly of air foils and at least one, the Ryan reference, mentions the use of quick-release fasteners to hold the assembly in alignment before riveting same, none appears to take notice of the tacking problem, let alone suggest a solution therefor.
The above-mentioned assembly and positioning of panel elements in a jig, normally requires a considerable number of man-hours for installing what are only temporary fasteners, i.e. tacking as noted above.
Accordingly there is a need and market for a jig assembly method and apparatus that omits or eliminates tacking in the assembly of reinforced panels and otherwise obviates the above prior art shortcomings.
There has now been discovered method and apparatus for jig assembly and positioning of reinforced panels that employs a "no tack" concept that significantly reduces the man-hour costs in jig assembly preparation, for subsequent permanent fastening of reinforced panels, including aircraft panels.